The present invention relates to digital scanners, and more particularly, to a digital scanner for scanning relatively stiff hard copy documents along a generally curved transport path.
It is known to provided scanners for scanning of hard copy documents. Generally, this takes the form of a flat platen upon which individual documents are placed for scanning. However, this is quite limited and very manual intensive. It is also known to provide automatic feeders on a flatbed scanner whereby a plurality of documents are provided across the platen for scanning of the information thereon. In scanning of relatively stiff documents, such as photographic prints, a number of problems arise. The relatively stiff nature of the photographic print presents several problems with respect to transporting of the documents along a transport path. Another problem associated with photographic prints is the possibility of producing small scratches on the original photographic print. The producing of scratches or other imperfection to the surface of the photographic print can be quite upsetting to the owner as the original print often has sentimental value to the owner. This transporting problem increases when a hard copy photographic print is transported along a curved path. Thus it is important to maintain a photographic print in its best possible condition. Another problem associated with scanning of a relatively stiff hard copy document, is the sticking of the document against the platen which can result in poor image quality and/or potential jamming of the print within the machine. Another problem that may arise in transporting a photographic print along a curved transport path in a scanner is that the leading edge of the photographic print can catch very easily and thus get damaged and/or cause possible jams.
It is important in the scanning of photographic quality images, that the best possible quality image be obtained. If the photographic print is not maintained properly against the scanning platen, various image defects may result. For example, there is a possibility that a magnification shift will occur due to the fact that the print is not always kept at the same distance from the scanning device. Another problem is that the image may have a keystoning effect due to the print not being maintained against the platen during scanning.
Thus, there is a need to provide an automatic scanner for scanning a plurality of relatively stiff documents without damage to the document and maintaining a high degree of quality in the images that are captured.
In accordance with one aspect of the present invention there is provided a digital scanner for scanning a sheet document comprising:
a transport path along which the documents travel;
a transport mechanism for moving the document along the transport path;
a platen having upper engagement surface, a leading edge and a trailing edge;
a sensor for digitally capturing an image on the document which is transported past the platen;
a first guide surface in the transport path adjacent the leading edge and a second guide surface in the transport path adjacent the trailing edge, the first guide surface and the upper engagement surface forming a first air gap, and the upper engagement surface and the trailing edge forming a second air gap as the document passes the platen.
In accordance with another aspect of the present invention there is provided a digital scanner for scanning sheet documents comprising:
a transport path along which the documents pass;
a transport mechanism for moving the document along the transport path;
a platen having an upper engagement surface, a leading edge and a trailing edge;
a sensor for digitally capturing an image on the documents which are transported past the platen;
a first guide surface in the processing path adjacent the leading edge, the first guide surface being positioned above the leading edge.
In accordance with yet another aspect of the present invention there is provided a digital scanner for scanning sheet documents comprising:
a transport path along which the documents pass;
a transport mechanism for moving the document along the processing path;
a platen having an upper engagement surface, a leading edge and a trailing edge;
a sensor for digitally capturing an image on the documents which are transported past the platen;
a pressure applying member disposed opposite the upper engagement surface for applying a pressure against the document as it moves past the upper engagement surface, the pressure applying member applying a substantially uniform pressure against the document.
In accordance with still another aspect of the present invention there is provided a digital scanner for scanning sheet documents comprising:
a transport path along which the documents pass;
a transport mechanism for moving the document along the processing path;
a platen having a upper engagement surface, a leading edge and a trailing edge;
a sensor for digitally capturing an image on the documents which are transported pass the platen;
the transport path including a first guide surface adjacent said leading edge and a second guide surface adjacent the trailing edge, the first and a first guide surfaces being substantially continuous and smooth.
In accordance with another aspect of the present invention there is provided a digital scanner for scanning a sheet document comprising:
a curved transport path along which the documents travel, the curved transport path comprising a channel having an outer guide surface and an inner guide surface;
a transport mechanism for moving the document along the transport path;
a scan gate located in the inner guide surface, the scan gate comprising an opening in the inner surface;
a sensor for digitally capturing an image on the document which is transported past the scan gate;
a biasing member for maintaining an area of the document to be scanned at the scan gate at a substantially constant distance with respect to the sensor as it passes by the scan gate.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.